1. Field of the Invention
The present invention relates generally to the field of aviation, and particularly to a modular aircraft having interchangeable wing and powerplant modules. The aircraft is particularly adapted as a remotely or autonomously controlled unmanned aerial vehicle (UAV).
2. Description of the Related Art
Virtually all aircraft are designed and engineered to optimize their configurations for specific mission requirements. For example, a long range reconnaissance aircraft requires significantly more fuel than would a short range fighter or interceptor aircraft, while speed may not be critical for a reconnaissance aircraft operating at extreme altitudes. This necessitates different wing configurations and may necessitate different engine configurations as well, depending upon the speed, altitude, and duration desired for each mission.
Accordingly, aircraft intended for fighter interceptor missions are generally configured with relatively short wings to minimize frontal aerodynamic drag for maximum speed, while also being equipped with a relatively powerful engine(s). Such aircraft might also be used for reconnaissance, but only for shorter range missions due to the fuel consumption and relatively small onboard fuel capacity provided by the interior volume of the relatively small wings. On the other hand, a long range reconnaissance aircraft is generally provided with wings of relatively large span and high aspect ratio to minimize induced drag and to maximize range. This is also true of other aircraft intended for long range missions or operations.
As a result, aircraft manufacturers have developed a wide array of aircraft having major differences in their configurations in order to optimize those configurations for their intended missions or operations. Examples of such may be seen in the products of a single manufacturer, e.g., Lockheed-Martin. The Lockheed Aircraft Company (before merger with Martin) manufactured the U-2, a long range, high altitude reconnaissance aircraft with extremely high aspect ratio wings and powered by a single turbojet engine. More recently, Lockheed merged with the Martin Aircraft Company to become Lockheed-Martin, which company (in partnership with other aerospace companies) produces the F-35 fighter, a short wing twin turbojet aircraft of relatively limited range and endurance.
The two aircraft types noted above were designed and manufactured as completely separate and distinct airframes powered by turbojet engines having quite different characteristics. Thus, in order to have aircraft capable of fulfilling both the fighter-interceptor role and the long range reconnaissance role, it was necessary for the military to purchase two completely different aircraft.
Other attempts have been made to provide multirole aircraft, e.g., the General Dynamics F-111 and the Grumman F-14 with their “swing wing” variably adjustable wing sweepback. The wings on these aircraft pivoted rearward to reduce the effective aspect ratio and frontal area for high speed flight, while pivoting forward to reduce the sweep angle and stall speed for takeoff, landing, and subsonic flight. However, the wings remained permanently attached to the aircraft in each aircraft type. They were not readily removable, and no other wing configurations were provided to adapt the aircraft for different missions or operations. Moreover, each aircraft was equipped with only a single engine configuration that was essentially permanently installed, excepting provision for removal for maintenance.
A number of retrofit devices and attachments have been developed for addition to existing aircraft. For example, winglets for attachment to the wingtips of an aircraft have been developed, to reduce the losses or spillage of air around the wingtips. However, these various attachments and retrofit devices are generally not modular in nature, and cannot be readily detached and/or reattached to different aircraft structures. The subject aircraft structures would require redesign in order to have multi-operational capability.
Thus, a modular aircraft solving the aforementioned problems is desired.